Synergists to aerosol insecticides



Patented Apr. 4, 1944 SYN ERGISTS T AEROSOL INSECTICIDES William N. Sullivan, Washington, D. 0., and Lyle D. Goodhue, Berwyn. Md., assignors to the United States of America as represented by Claude R. Wickard, Secretary of Agriculture, and his successors lnofllcc No Drawing. Original application September 30,

1941, Serial No. 412,960.

Divided and thisapplication-January 7, 1944, Serial No} 517,359

(Granted under the act 01 March 3, 1883, as amended April so, 1928; 310 o. o. 757) 3 Claims.

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described and claimed, if patented, may be manufactured and used by or for the Governmentof the United States of America for governmental purposes without the payment to us of any royalty thereon.

This is a division of our copending application for patent, Serial No. 412,960, filed September 30, 1941.

Our invention relates to materials which will increase the efiectiveness ol insecticides in aerosol form.

Certain agents which may or may not be toxic in themselves when added to aerosol insecticides greatly increase the rate of mortality. The increased toxicity obtained by the combination of such materials is often referred to as synergism and the added material a synergist. Therefore, in these terms. the general object of our invention is the provision of materials suitable as synergists for aerosol insecticides.

purposes of this invention belong most-frequently to the class of chemical compounds which are surface active in non-aqueous solvents or which act as detergents in non-aqueous solvents. These compounds, in general, contain polar groupings such as the hydroxyl, the carboxyl, the amine, the ammonium, or the sulfonic acid, alone, in multiple, or in combination, which is attached to some long chain aliphatic radical, or, in some cases, an aromatic radical.

Substances acting as detergents or surface active agents in non-aqueous media can be easily applied by the usual methods of aerosol production, but this invention is not limited to these substances because different methods of aerosol production can be used with different types of synergists. In this class of chemical compounds we have found the fatty acids, the mono esters of fatty acids and ethylene or propylene glycol. of glycerine or sorbitol, to be especially suitable as well as fatty acids in combination with amines such as methanolamine, sulfonated aryl and alkyl radicals alone or combined with an amme.

There are many process which can be used to apply these materials in the form of aerosols, such as spraying into the atmosphere, vaporization, by chemical reaction, by spraying on a heated surface, and so forth. Although this invention is not limited to any particular method of application, our preferred method of application comprises dissolving the synergist in the insecticide, if the insecticide is a liquid, or dissolving it in some solvent common to both if a solid, and sprayng the solution on a heated surface, whereby an aerosol is formed composed of both the synergist and the insecticide.

A synergist to an insecticide in aerosol form is not necessarily also a synergist to an insecti-' cide in spray form, even of the same compound. Actual tests have disclosed that an agent which possesses little or no effect as a synergist to an insecticidal spray may be extremely effective as a synergist to an insecticidal aerosol. The reason for this is not apparent, but it would seem that the mere wetting of the insect cannot explain the action. i

The following results were obtained using synergists in accordance with this invention. These results were obtained on the basis of preliminary tests first carried out in a small chamber of 7 cu. ft. and then on a larger scale in a 216 cu. ft. chamber. In' each test from 500 to 600 flies were used. Six-tenths of a pound of o-di-' centrations and it was found that little is gained by adding more than 10%.

The following is a list 01' substances which were tested as synergists at a concentration of 0.06 lb. in 0.6 lb. 01 o-dichlorobenzene' per 1000 cu. it. against the housefly. the percentage of kill in each case being indicated in the right hand column:

. Per cent ki Other insecticides were used against the American and German cockroach at a concentration 01. 1.5 lbs. per 1000 cu. it. One-tenth of the insecticide was replaced by a synerglst. A mortality or 100% was obtained with theiollowins: methyl chloroacetate plus lauric acid, epichlorohydrin plus lauric acid. epichlorohydrin plus oleic acid, ethyl dichloroacetate pluslauric acid, ethyl dichloroacetate plus oleic acid, beta-chloroethyl chlorocarbonate plus lauric acid, beta-chloroethylacetate plus lauric acid, tetrachloroethane plus lauric acid, and o-dichlorobenzene plus lauric acid. In all cases where olelc acid was eflective,

lauric acid was also round to be eflective and vice versa. The kill without a synergist was always less than 100% and usually less than 50%.

In a 1100 cu. ft. room, naturally infested with cockroaches, more than 5000 were killed in 18 hours and none were found living, using 1% lbs.

I of o-dichlorobenzene with 3% lauric acid and 2% oleic acid. Excellent results were also obtained in a 3200 cu; tt room.

Tests were alsg conducted against the carpet beetle larva, the 'coniused flour beetles and crickets. The halogenated esters in combination with anyone of the synergists mentioned above are extremely toxic to the confused flour beetle and produce a high mortality to the carpet beetle Among 80 compounds tested against the housefly in the form of aerosols, in combination with synergists of the typ mentioned above, are 3- chloroacenaphthene, 2-clilorofluorene, 3-chlorodibenzqfuran, chlorinated diphenyls, halogenated naphthalenes, halogenated esters, halogenated ketones, carbazole, thiocresol and halogenated phenols. Thesynergist was shown to be respon-. sible in each case for an increase in toxicity.

Having thus described our invention, we claim:

1. An insecticide in aerosol form comprising ortho-dichlorobenzene and an agent chosen from the group consisting of diglycol laurate, propylene lycol oleate, propylene glycol laurate, sorbitol laurate, and monoglycol laurate.

2. An insecticide in aerosol form comprisin ortho-dichlorobenzene and lauryl sulfate.

3. An insecticide in aerosol form comprising ortho-dichlorobenzene and sulfonated naphthalene.

WHMAM N. SULLIVAN. LYLE D. GOODHUE. 

